1. Field of the Invention
The invention relates to a sealing strip used in the construction of insulating, double pane structures. More particularly, the invention relates to a sealing strip composition comprising of a polymeric base material(s),a cross linking agent, an adhesion promoter, fillers, molecular sieves, plasticizers and less than 10% tackifier.
2. Description of the Prior Art
Various sealing structures have been developed for use in the fabrication of insulating glass structures. These sealing structures are generally positioned between adjacent panes and act to maintain the panes in a spaced relationship. The sealing structure must also prevent the passage of undesirable materials within the space defined between the adjacent panels. The passage of, for example, water vapor, leads to the formation of undesirable condensation between the panes. Once such condensation has made its way within the space between the panes, the double pane becomes unuseable.
With this in mind, a sealing structure must be optimized to maintain the spacing between the panes, adhere to the surface of the panes so as to create a barrier to the passage of vapor between the sealing structure and the pane, and be substantially impermeable to vapor through the sealing structure itself. A variety of sealing structures are known to exist, but each is known to possess shortcomings requiring modification of the base sealing material through the inclusion of various structural additives such as spacers and vapor barriers.
For example, and with reference to U.S. Pat. No. 5,855,972 to Konrad H. Kaeding, a sealant strip for use in the fabrication of insulating glass is disclosed. In the ""972 patent, Kaeding provides examples of using a deformable sealant strip to manufacture insulating glass for use in window systems. Although he makes some strides in overcoming previous deficiencies in analogous systems, he fails to completely resolve the issues of simplicity, resistance to compression, good adhesion and ease of manufacture. He gives many examples of xe2x80x9cgrafting polymers onto the backbone of the Exxon Exxpro polymersxe2x80x9d, but he does not obtain the desired product without further manipulation. However, Kaeding was not able to resolve all issues and obtain the optimum synergy.
Kaeding claims to provide excellent adhesion, but offers no data. He claims to have a system that is resistant to compression, but uses xe2x80x9cstaplesxe2x80x9d within the sealant strip to maintain the desired dimensions and to prevent compression. In addition, he discusses the use of plastic and/or metal vapor barriers to prevent the ingress of water and other external materials into the cavity of the insulating glass unit. He also uses several complex xe2x80x9ccuringxe2x80x9d systems.
All these issues are overcome in accordance with the present invention by the simple use of polymers and a dual curing/adhesion promoting system. The present invention overcomes these deficiencies with a simplified cross-linking system to prevent compression which occurs over a period of time and a grafting of silane type adhesion promoters onto the backbone of the Exxon polymers.
Also, in one embodiment of the present invention the present sealing system takes advantage of using a liquid silane compound and a liquid cross-linking agent, both of which facilitate the ease of incorporating these materials into the elastomer matrix to provide a far more homogeneous product.
It is, therefore, an object of the present invention to provide a composition adapted for use as a sealing strip in the manufacture of insulating structures. The composition includes a polymeric base material(s), a cross linking agent, an adhesion promoter, fillers, molecular sieves and plasticizers and less than 10% by weight tackifier.
It is also an object of the present invention to provide a composition wherein the cross linking agent is chosen from the group consisting of divalent metal oxides, divalent salts of organic fatty acids, organic fatty acids, zinc oxide, zinc stearate, stearic acid, zinc octoate (solution and solid), tin octoate and calcium stearate.
It is a further object of the present invention to provide a composition wherein the cross linking agent is zinc octoate in solution.
It is another object of the present invention to provide a composition wherein the adhesion promoter is chosen from the group consisting of organopolysiloxanes, organosilanes, organoaminosilanes, epoxysilanes, thiosilanes, organosilanols, alkoxysilanes, acetoxysilanes, and ketoxysilanes.
It is yet another object of the present invention to provide a composition wherein the adhesion promoter is an organoaminosilane.
It is still a further object of the present invention to provide a composition wherein the tackifier is chosen from the group consisting of organic monomers, oligomers and polymers, hydrogenated C5 and C9 resins, C5 hydrogenated resins, polyterpene resins, pentaerythritol esters of hydrogenated wood resins, phenolic polyterpene resins, alpha pinene resins, dipentene resins, hydrogenated C5 esters, cycloalkene resins, phenol-aldehyde resins, rosin acids and esters, dipentene resins, petroleum hydrocarbon resins and alkyl aromatic hydrocarbon resins.
It is also an object of the present invention to provide a composition further including one or more fillers.
It is also another object of the present invention to provide a composition wherein the polymeric base material includes compounds comprising polyisobutylene/polyisoprene copolymers, polyisobutylene polymers, brominated olefin polymers, copolymers of polisobutylene and para-methylstyrene, copolymers of polyisobutylene and brominated para-methylstyrene, butyl rubber-copolymer of isobutylene and isoprene, ethylene-propylene polymers, polysulfide polymers, polyurethane polymers, and styrene butadiene polymers.
It is a further object of the present invention to provide an insulating glass structure including a first pane, a second pane and a sealing strip as discussed above positioned between the first pane and the second pane.
Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention.